在 VBA 中使用 Base64 将图像插入工作表？

Question

我正在尝试使用 Base64 将图像插入到带有 VBA 的工作表中，但我在任何地方都找不到如何正确执行此操作的示例。

我为图像设置了一个字符串，例如：

vLogo = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZoAAABfCAY"

我只想执行以下操作，但不是寻找图像文件，而是将图像存储在 VBA 中。

Sheets("Sheet1").Pictures.Insert (Application.ActiveWorkbook.Path & "\vLogo.png")

我什至看过做类似的事情：

' Write the image to file
Dim myFile As String
myFile = Application.ActiveWorkbook.Path & "\temp.png"
Open myFile For Output As #1
Write #1, vLogo
Close #1

' Insert the image
Sheets("Sheet1").Pictures.Insert (Application.ActiveWorkbook.Path & "\temp.png")

' Delete the temp file
Kill Application.ActiveWorkbook.Path & "\temp.png"

但我不知道如何将 base64 编码的图像写入文件。

Answer 1

MSXML 库中有一个base64 编码，可以在VBA 中使用。网上有很多例子，核心功能不断弹出：

• Experts Exchange 引用了下一项
• Something by a Tim Hastings according to Wayback machine (2005!)
• Stack Overflow
• Travis Hydzik's blog

我基本上提升了相同的代码，它接受一个字符串并返回一个 base64 字节数组，然后使用 OP 的临时文件方法将图像加载回工作表中。我已经整理了一下，使用了后期绑定并进行了一些测试。这些测试在 Excel 2010 上对我很有效：

在问题中测试base64字符串似乎不起作用：

iVBORw0KGgoAAAANSUhEUgAAAZoAAABfCAY

给予：

代码：

Option Explicit

Sub Test()

    Dim strTempPath As String
    Dim arrTest(1 To 3) As String
    Dim intCounter As Integer

    'base 64 image examples
    'red dot
    arrTest(1) = "iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDIBKE0DHxgljNBAAO9TXL0Y4OHwAAAABJRU5ErkJggg=="
    'little face logo
    arrTest(2) = "R0lGODlhDwAPAKECAAAAzMzM/////wAAACwAAAAADwAPAAACIISPeQHsrZ5ModrLlN48CXF8m2iQ3YmmKqVlRtW4MLwWACH+H09wdGltaXplZCBieSBVbGVhZCBTbWFydFNhdmVyIQAAOw=="
    'Stack Overflow logo
    arrTest(3) = GetSOLogoBase64

    'use workbook path as temp path
    strTempPath = Application.ActiveWorkbook.Path & "\temp.png"

    For intCounter = 1 To 3

        'save byte array to temp file
        Open strTempPath For Binary As #1
           Put #1, 1, DecodeBase64(arrTest(intCounter))
        Close #1

        'insert image from temp file
        Sheets("Sheet1").Cells(intCounter * 4, 1).Select
        Sheets("Sheet1").Pictures.Insert strTempPath

        'kill temp file
        Kill strTempPath

    Next intCounter

End Sub

Private Function DecodeBase64(ByVal strData As String) As Byte()

    Dim objXML As Object 'MSXML2.DOMDocument
    Dim objNode As Object 'MSXML2.IXMLDOMElement

    'get dom document
    Set objXML = CreateObject("MSXML2.DOMDocument")

    'create node with type of base 64 and decode
    Set objNode = objXML.createElement("b64")
    objNode.DataType = "bin.base64"
    objNode.Text = strData
    DecodeBase64 = objNode.nodeTypedValue

    'clean up
    Set objNode = Nothing
    Set objXML = Nothing

End Function

Function GetSOLogoBase64() As String

    GetSOLogoBase64 = ""
    GetSOLogoBase64 = GetSOLogoBase64 & "iVBORw0KGgoAAAANSUhEUgAAANAAAAA4CAMAAAC7bYapAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsMAAA7DAcdvq"
    GetSOLogoBase64 = GetSOLogoBase64 & "GQAAADJUExURSIkJi8wMi8xMzw+QD0/QUpMTktNTlhaW1lbXGZnaWdoanR1dnV2d4KDhIOEhZCRkpGSk56en56foKusraytrrm6u7q7u7y7u8"
    GetSOLogoBase64 = GetSOLogoBase64 & "TDw8fIyMjHx8jJyczLy83MzNXV1tnY2N3d3ePj4+bl5e7u7vHx8fLy8vSAJPSHMPSIMfWPPvWQP/aXTPaYTfafWvegW/enZ/eoaPivdfiwdvm"
    GetSOLogoBase64 = GetSOLogoBase64 & "3g/m4hPm/kfrAkvrHnvrIn/vPrPvQrfzXuvzYu/zfyP3gyf3n1f7v4//38f///4l4PkAAAATsSURBVGje7Zh5e5tGEIeXS4CQDArGKlVEQ7pF"
    GetSOLogoBase64 = GetSOLogoBase64 & "cn0kjq8qqiqJ7/+hOjO7LAgdsRWnjXjYPyxgl2HeOX67j1nesMFaoBaoBWqBWqAW6GcGWs+bBbS8zuZNAlpfZtl01aQMzbIsu25UD90B0X1Dg"
    GetSOLogoBase64 = GetSOLogoBase64 & "Nb05wqI5o0AmmczkoXJSbXRfqDlNMse8OL5pNqIHZSD7DOW3Se4eGxAyWGtZdcrod3ZogGisEI9mC4BDX/XDZDtNRYbSgO20e2rbQfBdzrHz4"
    GetSOLogoBase64 = GetSOLogoBase64 & "MgzOPgNYb2AC3l7z0SPRzZRuw7T76JyRizc5+9xtCepZfTp3VVGqiNlvVVYZD+SKAOezMgxJg+rSrSsMwms61lNot/IFAKIJYfvgkQnndgfFm"
    GetSOLogoBase64 = GetSOLogoBase64 & "V0jBf5v8xUAwgaP9NSm5xI5EWUhqudq16NVA6Gu1p/1H6IqDRiB+rckuZpdsFSsOkmp8LkJ3zlIDejdDFNOg6Z6qfLs6c7jteAvEgSOjiHJtc"
    GetSOLogoBase64 = GetSOLogoBase64 & "73EqJo/aHi4GxUTAhfd2hLc9jkAdp18CJV1sKgcgDZihJqbX89yF5+k3ZXslka6/5rNFTXvwiwjEmBahWRpn5D61MtOjAggekPN5Ty7rcHRAx"
    GetSOLogoBase64 = GetSOLogoBase64 & "0d9cqQygd7r4i6K2aYoJHKChfI9AjFxCmasF+1DjxNC+rOSH65rIcQ4NEIE8nwIvqXBNQ81jBa4b0c89vED5IfiiVgxHAoBZs1Eh/HGsA2RNZ"
    GetSOLogoBase64 = GetSOLogoBase64 & "8pr2tAXFcG0oQW5JwJO3jbPwA0//LXPwoJ9TqrHLYjkeRqD/FEznTQIVfccAEE+QxLEY5y7pEPGnkg/DJF/XkUdfTeSvkg3Ooh5PY4xcXD9z3"
    GetSOLogoBase64 = GetSOLogoBase64 & "xCO0MZHz2AdFuevvwVeRldpndVSZ98GqPKOB3Oyyt3kOZhOqOWDm1jUe1gq5ypOJqwi+7oQbkyXUuZk28j62Dv1D62iFRuMqKcfv0NyRnttrQ"
    GetSOLogoBase64 = GetSOLogoBase64 & "HocfAFK1TPfAY1Y0y8cLA38TimkH44zhDXDQgoqk1YDAayMvbjFPCYRAs9BOoTH7gB5vJlk5pp+fa1oN2tML4gpQfObggA/FEL0KkM4sQVEBs"
    GetSOLogoBase64 = GetSOLogoBase64 & "ukXsPopFaHqmm8D2QoIGQZA5UI4+jHZ2QX0fjz+Qyrc/P5GIX3K84/j8W/qwEMNjImSQD2m2Ti2gVjINVndNSBwxBxQpRwHBNXmQt2FEBSzX9"
    GetSOLogoBase64 = GetSOLogoBase64 & "15N4CGw+Hv1a1odkfVB6fSD8Ph+42NMLKg4AVQzCxelBzfBArRcycvthxfSqwvzjW66uhqix4AMssVoAe6jk1lkR33RUDizPB8t9wGyikXtvx"
    GetSOLogoBase64 = GetSOLogoBase64 & "gXPaQxnjtpGBJWSS9FiSh8K/UXGGAHwQq9h6HMpXS666IB1PKsxNo8VQbq11ACZh1N4BS/K4ne6Y8KSRMT4vdPEguOtIvklxDqoQOFtKu3Fh3"
    GetSOLogoBase64 = GetSOLogoBase64 & "AcViH+tcJIHMtCU5BBk/BPSY1caiCtRzUrnvo8Z2ybVucUQA+xr1Z9rpqaNPXxRdojqF9kBoLnluCdUEEO0AimV7WcUyDd0fFBz42MqPBuJQK"
    GetSOLogoBase64 = GetSOLogoBase64 & "t0g6OloBLzXHawe0wkcXSv2P9MhPVZnOW3TcVeE01M7jld46u3MkNhu/JxLIi0p4kOdMygCc2SGQOTQqkU2EtcAA7wPVaN5qSwx/D4ejNRpO2"
    GetSOLogoBase64 = GetSOLogoBase64 & "I6MaQerLPC0t9CQCJy2Y139xD4LJQxDwHJ8OS+a8jOScqt+EWiIMZ2D53EP0laoBMA+nW8c/xyskD7Rwv0EwB9ODQ+NuBfwac4WqAWqAVqgVq"
    GetSOLogoBase64 = GetSOLogoBase64 & "gFuj/HP8CZQ0/RA2L6ggAAAAASUVORK5CYII="

End Function